Acceleration at High Speeds 48' Windsor HELP

[windsor48]

Hi all,

Thanks for any help or insights...

 

 I'm having an issue with my 48' Windsor when accelerating to high speeds (50mph+). Even if I floor the pedal, it can't maintain speed or accelerate past that point. If you take your foot off the gas it's smooths out but once you reapply the gas and acceleration kicks in it hesitates and won't gain speed. Picture being unable to go more than 45mph on the interstate...

 

It runs great up until that point. It's all factory with the spitfire and two speed fluid drive that I keep it in high gear throughout my drive. Going to the grocery store or cruising  around town I've experienced none of this issue.

 

When I got it the wiring was kinda a mess but followed my manual and pretty sure all that's resolved. But if something wiring related could cause this please let me know and I'd double check that! 

 

The carborator was just rebuilt, fuel filter is clean, all normal maintenance has been done.

 

I've got a nice weekend to tinker and try to resolve so any and all ideas welcome..... 

 

Thanks guys!!! I always appreciate the knowledge found in this group!

[Adam H P15 D30]

New points?  Sometimes new points have weak springs and float at higher rpm. 

 

Adam

[Paulo Windsor]

Hello Windsor48

I had some years ago the same problem on my 47 Windsor.

After spending money on a new fuel pump,check everything eletrical,the problem was simple.

Where the fuel enters on the carburator its the float needle seat,ok. Part number 690676 on my book.

Inside of that on my case there is a rubber hole that over the years closes and at a moment there wasn´t enough fuel going into the carb. Open a little without damage the needle seat and go on road drive 60-70 mph without any problems for more 70 years!!!!!!!!!

I hope this may help you.

From Portugal

Paulo

Edited April 28, 2018 by Paulo Windsor

[Niel Hoback]

With the engine off, have an assistant press the accelerator to the floor while you look down the carb throat to see if the throttle plate is actually opening all the way. Linkage is adjustable.

[windsor48]

Thanks for the responses. I've checked over the carborator, the needle seat, and throttle plate. They all appear good.

 

BUT here's where things get goofy. I've attached a photo of a wire. When I got the vehicle this wire was disconnected as shown. I attached it according to the wiring diagram to the ignition coil. When I did this it smoothed out a shift problem where my windsor would "kick" (jolt forward) at a stop if stationary for more than about 5 seconds. 

 

Around town drove great... but lost acceleration at high speeds. While I disconnected this wire this morning after checking through the carborator. Test drive and voila worked great on the freeway. Drove it on and off several times and maintained speed for entire stretches without issue. Of course the "kick" came back though!!!

 

SO.... what the heck is going on here?!?!? My understanding is that wire runs from the transmission relay.... correct??? I can post more photos if needed.

 

thanks again!!

[P15-D24]

Check the centrifugal  advance on the distributor?

[dpollo]

Put a vacuum gauge on it.  A low reading might indicate a plugged muffler which would cause the symptoms you describe.

[windsor48]

5 hours ago, P15-D24 said:

Check the centrifugal  advance on the distributor?

 

Forgive me if this is a common thing... but how is this done?? 

[P15-D24]

The advance is under the distributor plate. Make sure both springs are attached and the weights are free to move outboard as it is spun. To check, disconnect the vacuum advance and plug the carb side. Then with a timing light bring the engine up in rpm checking the timing with the gun. Here are the number for a D24, your should be similar but you should check your manual.  You can do a similar check with the vacuum advance using a vacuum gun. I've found if the advances aren't working correctly the car will fell like it can get out of it's own way and top speed will be lower.  

 

[greg g]

Well it seems related to that wire if it runs out well disconnected.  Check the repair section of the Imperial club website, they have a lot of info about trouble shooting the semi auto transmission including the original tech training film strip presentations all digitized with sound and all.

[greg g]

Which wire?

[windsor48]

22 minutes ago, greg g said:

Which wire?

 

Its the wire that runs from the PRI. (On the kick down feed relay) to the ignition coil. Here's the photo from my manual.

 

Its like it won't shift into 4th gear when this is connected so tops out at 45mph. BUT WHY??? I don't see why the kickdown would cause the issue when stopped when disconnected, then reconnecting causes it to not engage 4th gear. 

 

Or im I way off base with my assumptions....??

Edited April 29, 2018 by windsor48

[Dodgeb4ya]

The trans won't upshift if the wiring for it is connected wrong.

 Both wiring diagrams are not for your car.. the ones posted first and your own. The diagrams shown are for the 1949-53 and yours.... late 1942 M-4 Vacamatic

Shown is the correct 1946-48 Chrysler M-5 wiring for the transmission circuit......

http://www.imperialclub.com/Repair/Lit/Master/012A/page21.htm... more info

As to what wire is  connected up wrong you will have to trace them out.

With the relay fuse out the trans will immediately upshift but not downshift until a complete stop with the clutch pushed down.

No power to the downshift solenoid.

If the solenoid has power the trans will not upshift and 45 will be about tops! Don't blow up the engine!

[greg g]

Sometimes when you put up a bunch of incorrect suggestions out there, it attracts the folks who actually know what is wrong.  It is kind of like fishing, ya gotta have the right bait.  Thanks dodgeb4ya.

[Dodgeb4ya]

They should'a made it simpler for all of us on all the different versions of transmissions in the 40's and early 50's for us Gregg!

Took me years to figure them all out.

[windsor48]

So... back to basics but confirmation is important. Can you help me with which wire goes into the the positive of the ignition coil? Right now the wire running from the Coil to the distributor is ran thru the negative of the ignition coil... is that correct?

Edited April 29, 2018 by windsor48

[DonaldSmith]

Yep, your car should be positive ground.  Two wires at the positive post of ignition coil, one wired to the distributor, and one, the through the transmission relay, to the interruptor switch.  The distributor and the interruptor switch go to ground, at their own proper time.   

[windsor48]

5 minutes ago, DonaldSmith said:

Yep, your car should be positive ground.  Two wires at the positive post of ignition coil, one wired to the distributor, and one, the through the transmission relay, to the interruptor switch.  The distributor and the interruptor switch go to ground, at their own proper time.   

 

So two wires to the positive on the right side of the coil and one wire connected to the negative. As shown in photo. Time for a quick test drive!!! Glad the rain hasn't come in yet!!!

[windsor48]

This wiring configuration appears to have corrected the issues. No problem getting to freeway speeds and no lunging a stops. Makes sense that the previous owner wired the coil wrong, then to "correct" the acceleration just disconnected the relay. Crazy a simple thing caused such a headache this weekend.

 

Thanks to all who helped and advised. I really appreciate it! All this gave a good portion of my car a look though which isn't a bad deal either.

 

BIG THANKS!!!!!

[greg g]

Glad that worked.Enjoy your ride.  You weren't running out of power you were running out of gear ratio.